Vacuum or pressure gage.



J. F. SIMMANGE & J. ABADY.

VACUUM 0B. PRESSURE GAGE.

APPLICATION FILED JULY 26,1910.

11,064,555, Patefited June 10,1913.

and the position of the union.

VACU Hi 0E, PRESSURE GAGE.

Specification of Letters Patent.

Patented June to, 1913.

Application filcd July 26, 1910. Serial No. 573,629.

To all w how it may concern.

le it known that we, .lonu l iucunmcn SiiunAnon and Jieoons Armor, subjects of (lreat Britain. residing, respectively/at l l l estminster Palace Gardens, London, S. K, and Fountain Court, Temple. London, Vi". (1, England, have invented certain new and useful ln'iprm'ements in Vacuum or Pressure Gages, of which the following is a specification, reference being had therein to the accompanying drawings.

In many types of pressure or vacuum gages the pressure of a fluid is measured by the defornuition produced on a flexible container into which the fluid is led. in such gages, 0., in a Bout-don pressure gage, for

high pressures, or in a vacuum or pressure gage of the aneroid barometer type for low pressures, one part of the flexible container is fixed to the base or framework of the in strument, and the n'iovement of another part is tral'ismitted to a, hand moving over a ial, or to a pen marking upon a chart; the dial or chart having a suitably graduated scale,

said hand or pen ind :ating the pressure of the tluid. In many pressure gages equal increments of liuid pressure are not represented by equal move.- menls of the hand over the dial. while the friction of the mechanism is often such that an appreciable lag of the hand is apparent as the pressure rises and falls.

(lur present invention relates to the mechanism which transmits the movement or deformation of the tlexible container to the: hand or pen. and provides means for dial or chart to correspond with equal incrcmei'its of pressure, means for adjusting or ralibratiug the instrument to corres 30nd with the scale engraved on the dial or chart, means for setting the hand or pen so that the zero of the scale corresptnids to zero or at lnospheric pressure, and means for reducing to a. minimum the friction of the mechanism so that there is no appreciable lag of the hand or pen as the pressure rises or falls. p c Our invention also relates to the well making equal divisionsol' the scale on the 'lfllOWll flexible box or bellows diaphragm used for low pressure gages, and provides a bellows diaphragm of sufficient strength and elasticity to resist the difference of pressure on its outside and inside surfaces, and capable of resisting chemical action by the particular gas or liquid for which the partieular pressure or vacuum gage is designed.

Figure 1 is an elevation partly in section and Fig. 2 is L plan showing our invention as applied to a barometer or to a vacuum or pressure gage for low pressure. Fig. 3 is a detail view illustrating the mode of securing the indicator hand to the spindle.

The forms of construction of the bellows diaphragm are well known. In one form, the box is made of a pair of circular disks corrugated cmicentrically and soldered or otherwise fastened together at their peripheries. (Joe of the disks is fastened at. its center to a suitable block which serves to fasten it to the frame of the instrument and to give coinmunicat-ion from the inside of the box by a pipe to the vessel containing the 'gas. the pressure of which is to be. measured. ltnother form of box is made from several .pairs of such disks each (with the exception of the last of the series) being pierced by a small central holy. the adiacenl being soldered or otherwis pairs ointed together at the central holes. To

give the necessary liexiblity the thickness of the. disks must be very small. o find that when such pressure gages are used to n nsure. the pressure of corrosivi-e gases or liquids. the box made in the ordinary way is soon corroded away. This occurs in many cases with gas from lines or furnaces, the presence of sulfur, for example. being very detrrnnmtal to the metallic box. For making vacuum or pressure gages it has been proposed to use steel or copper diaphragms electroplated or otherwise coated with noncorrodible metal. it has also been proposed to use separate protective sheaths of copper or other non-corrodible metal. in conjunction with steel diaphragms. Neither of the above methods form part of our invention, but on the contrary, we'find that the electroplating of steel diaphragms att'ords insulticient protection against corrosive action in many cases.

Our invention consists, in, and is restricted to, the use of composite disks each made up of two sheets of metal united together by soldering or the like process.

In our invention we ma kc each disk from two sheets of metal which are united together face to face, to form one composite corrugated disk. The outer sheet exposed to the atmosphere is of steel, copper, bronze, German silver, or other suitable material having the necessary strength and elasticity. The inner sheet, which exposed to the gas or liquid may be of lead, tin, silver, gold. platinum or other suitable material selected not on account of its hardness, strength or elasticity, but solely on account of its properties in resisting chemical action by the particular gas'or liquid for which the particular pressure or vacuum gage is designed.

In making our composite corrugated disks we may hold the sheets loosely and spin, stamp or press the concentric corrugations while the two sheets are separate from each other, then by heating to a suitable temperature andv pressing them together, using it necessary a suitable soldering material, the two sheets are united to torm'one composite corrugated disk. Or, the two sheets may be united together when flat, and the corrugations may be spun, stamped or pressed on the composite disk.

The flexible container or bellows diaphragm 1 (Fig. 1) is fixed to the base plate 2 of the instrument, the fluid being admitted by the pipe I.. If used as a barometer, the flexible container is exhausted of air and hern'ietically sealed, no pipe being required. The movement of the upper part 3 of the flexible container under varying pressures ot' the fluid is transmitted to the hand 21 as follows :A link 4 adjustable in length by any well-known means has one end fixed to a. piece 3 rigid with the top of the flexible container, and its other end is jointed at 5 to one end of a slot ted bar b adjustable in position on a bar 7 integral with the spindle 10. Thus the radius at which the link 4 acts tending to rotate the spindle 10 can be adjusted. Integral with the piece 7 is a threaded wire 8 on which a counterweight t) can be clamped in any desired position. The conical ends of the spindle 10 are mounted on the ends of adjustable set screws 11 carried by the levers let, the set screws being clau'iped in position by the clamping nuts 12. The hand 21 is mounted on the spindle 10 and turns therewith, the details of the connection are described hereinafter. The end of the hand 21 swings over the graduated scale 23 engraved on the dial. mthe purpose ot adjusting the Zero reading of the hand on the graduated scale to correspond exactly Wllll zero or atmospheric 4 pressure the distance of the spindle 10 from the base plate 2 is adjustable as follows The two levers 14 are integral with or fastened to a spindle 10 the ends of which are suitably mounted on hearings in the sides of the frame 2. One of the said levers 14: is a bell crank lever, the arm 15 projecting vertically downward from the spindle 16. Attached to the lower end of the arm 15 is a stud 17' which carries an adjusting screw 18 having a milled head 19 on the end which projects through the case of the instrument. The other end of the adjusting screw bears against the side of the frame 2. Thus, by turning the milled head 19, the screw 18 alters the dist ance of the stud 17 from the side of the frame 2. The bell crank lever 14, 15, is thus turned through a small angle about the axis of the spindle 16, and the position of the spindle 10 relative to the flexible diaphragm can be adjusted.

The hand 21 is suspended from and turns with the spindle 10. For this purpose a trunnion 23* is clamped ti'rthe spindle 10. When used for a vacuum gage, the trunnion piece is clamped on the spindle in such a' position that the zero or atn'iospheric pressure is shown at. one end of the graduated scale, when used for a pressure gage, the trunnion piece is clamped in such a position that the zero or atmospheric pressure is at the other end of the scale. A ring 24 (Fig. 3) carries adjustable set screws 25, the conical ends of which engage with the ends of the trunnions 23*, and clamping nuts 26 retain the set screws 25 in position. The hand 21 is s01- dcred to the ring 24. A threaded wire 27 is integrally fixed to the ring and an adjustable weight 28 is screwed thereon, and is clamped in position by a clamping screw. The hand 21 being set at a slight angle with the wire 27 by adjusting the position of the wei 'ht 28, the end of the hand 21 can be madb to take up a-position close to, but not touching the dial 22*.

Claims.

1. A vacuum or pressure gage comprising a flexible box or bellows diaphragm, a rotatable spindle, a hand mounted against rotation thereon, adjustable means for causing the expansion and contraction of the diaphragm to rotate the spindle, and means for adjusting the instrument to correspond exactly with the scale on the dial, the said means coin]. -ising a base, an arm fixed to and depending from the spindle, and means for varying the distance between the base and the arm. i

2. A vacuum or pressure gage comprising a flexible box or bellows diaphragm, a base plate therefor, a rotatable spindle, a hand' piece 22 with projecting trunnions gounled against rotation thereon, adjust- In testimony whereof We afiix our signaa'ble means for causmg ihe expanswn and lures in presence of two witnesses. v can't-manna of the dmpm'a N11 to rotate the JNO. F. SIMWANCE.

spindle, and means for vmying the distance JACQUES ABADY.

beuveen the spindle and the base plate for Witnesses: adplstzng the lnstrument $0 corre pond ,ECIL ARTHUR GOODWIN, exactly mth the scale on the (11:11. JAMES FOREMAN. 

